The present invention relates to components and methods used in connection with ventricular assist device and interaction with the anatomy of a human, namely the heart and blood flood therethrough.
In certain disease states, the heart lacks sufficient pumping capacity to meet the needs of the body. This inadequacy can be alleviated by providing a mechanical pump referred to herein as a heart pump or a ventricular assist device (“VAD”), one example of which is illustrated in FIG. 6, to supplement the pumping action of the heart. Considerable effort has been devoted to providing a VAD which can be implanted and which can remain in operation for months or years to keep the patient alive while the heart heals, or which can remain in operation permanently during the patient's lifetime if the heart does not heal, or which can keep the patient alive until a suitable donor heart becomes available.
The VAD is typically connected to the heart, most commonly to the left ventricle. Typically, one end of an outflow tube is connected to the VAD and the other end is connected to the aorta. Once connected, the VAD and the heart both pump blood from the left ventricle to the ascending or descending aorta to improve blood flow. Alternatively, a VAD may be connected to the ventricle to assist the heart in pumping blood into pulmonary arteries.
The VAD 82 typically is connected to the heart through the use of a sewing ring or a VAD connector 50 (see FIG. 6), as disclosed in U.S. Published Patent Application Nos. 2004/0171905 and 2007/0134993, the disclosures of which are both hereby incorporated by reference herein as if fully set forth herein. The VAD connector may be in the shape of a ring and is attached to the outer surface of the heart, commonly through the use of sutures. A separate surgical tool is then used to cut or core a hole in the ventricle centered within the VAD connector. An inflow tube 84 (FIG. 6) extending from the VAD is inserted through the hole in the left ventricle. The VAD is then attached to the VAD connector such that the inflow tube 84 of the VAD is positioned within the central opening of the VAD connector 50. The VAD connector is used to clamp the inflow tube and thereby hold the VAD in position relative to the heart and form a seal around the inflow tube.
However, such connectors and configurations can potentially cause problems when the VAD is removed and/or replaced with a new VAD. For example, upon implantation of a VAD, using the above configurations, the heart wall, and related tissues, heal around the VAD structure. Once the VAD requires replacement, and the VAD structure is separated from the healed tissue, the risk of renewed bleeding or embolization may occur. Moreover, upon implantation of the new VAD, the healing process must recur, risking infection, prolonged bleeding, or other complications.
An additional drawback to the current configurations, of above, is that, during initial placement of the VAD or replacement of the VAD, the opening in the heart wall is open and thus blood from the heart may exit from the opening. To avoid massive blood loss, the patient may be subjected to cardioplegia (temporary stoppage of the heart), cardiopulmonary bypass, or both during implantation of the VAD, during removal of the VAD, or during implantation of a replacement VAD. Moreover, this hole in the heart wall may allow the inflow, through the hole and into the heart, of outside air, which can also cause complications for the patient.
For at least these reasons, a new device capable of securing a VAD to heart tissue, or other cardiovascular tissue, while alleviating or eliminating many of the issues above, is needed.